Well casing perforator



M. F. Algo. f 2,351,179

` WELL CASING PERFORATOR Filed Feb. 22. 1943 .INVENTOR I v l l n m5677772 Patented June 13, 1944 UNITED STATES PATENT oFFlcE I WELL (-JASslgFORA'OR Millie F. Alol, Maywood, Calif.

Application February No. 47li,666

12 claims.

My invention relates to well casing of the particular type forming the subject matter f U. S. Letters Patent #2,202,887 issued to me June 4, 1940, and the principal objects of my invention are, to generally improve upon and simplify the construction of the casing pertorator covered by my aforesaid patent, to provide simple and efficient means whereby the explosive charges in the firing chambers of the device are positively ignited in sequence, one from another, and fur'- ther, to construct the body of the perforator in sections, capable of being readily assembled or 'taken apart in order that a perforator oi' any desired length may be easily and quickly provided.

A further object of my invention is, to equip a casing perforator of the character referred to, Iwith simple and efficient means for preventing the explosive charges Within the body of the device from being ignited by hydraulic pressures encountered at great'depths, for instance,` ilve thousand or more feet.

With the foregoing and other objects in View, my invention consists in certain novel features of construction and arrangement of parts which will be hereinafter more fully described and claimed and illustrated `in the accompanying drawing in which:

Fig. 1 is a top plan view of a casing peri'orator constructed in accordance with my invention.

Fig. 2 is a longitudinal section, reduced in size, and taken on the line 2 2 of Fig. 1.

Fig. 3 is a horizontal section taken on the line 3-3 of Fig. 2.

Fig. 4 is a horizontal section taken on the line 4-4 of Fig. 2.

Fig. 5 is a vertical section taken lengthwise through the center of the weight used in iring the explosive charge igniting cartridge at the upper end of the tool.

perforators Fig. 6 is a horizontal section taken on the line 6 6 of Fig. 5.

Referring by numerals to the accompanying drawing which illustrates a preferred embodiment of my invention, I0, `III designate the cylindrical sections which. compose the main body of the tool, said sections being formed of metal, preferably steel, with each section provided in its upper end with an axially arranged threaded recess Il, and projecting from the lower end, is a threaded pin I2, adapted to enter the threaded recess in the next lower section.

Formed through each section III is an axial bore I3 and when the sections are assembled to form the tool, these bores provide a iiame duct which extends the entire `length ofthe body composed of said sections.

Screwed onto the pin I2 on the lowermost one of the 4sections I0, is a short cylindrical pilot block Il. generally known as a bull nose which serves to guide the tool as it is lowered into the well hole.

Screwed into the threaded recess in the upper end of the uppermost one of the sections I0 is a threaded pin I6, that depends from the lower end of a short cylindrical member I'I, the same forming the upper section of the tool and formed in the upper portion of this memberis an axial bore I8.

Intersecting bore I8, a short distance above its closed lower end, is a diametrically disposed bore I8 for the reception of a bolt 20, the head of which is countersunk at one end of said bore I9 and the threaded end of this bolt receives a nut 2|, which occupies a recess, formed in member Il around the bore I9.

Formed through the intermediate portion of bolt 20 is an aperture 22 through which passes the lower portion oi' the cable 23 used for lowering and raising the perforator in the well hole and the casing therein.

The distance from the bottom of the countersink which receives the bolt head, to the center of the bore I8, is slightly less than the distance from the underface of the bolt head to the centerof the aperture 22 and thus, after Athe cable has been passed through said aperture 22 and nut 2i is tightened on said bolt aperture 22 will be driven slightly out of registration with bore I8, thereby pinching and very securely clamping the cable to the tool.

Removably seated in the upper portion of upper section I'I is a tubular member 25 and the lower vend of this chamber is reduced in diameter to form a blank cartridge-receiving chamber 26.

Fitting snugly within tubular member 25 and slidable therein under an impact -of considerable force, is a iiring pin 21. After a blank cartridge such as C has been placed in chamber 26, a 'thin disc 21, preferably of steel and overlaid with a packing disc 2`|b`of rubber or the like, is positioned on tup of said cartridge and clamped thereagainst by screwing tubular member 25 downwardly. The construction Just described protects the cartridge against moisture and prevents said cartridge from being red as a result of the high hydrostatic pressure prevailing in deep wells.

Leading from the lower end of cartridge chamber 28 downwardly through the lower portion of section I'I and threaded pin I6, is a ame duct duct I3 in the uppermost one of sections III.

wardly from the barrel to pass'through and per- 'rne sliding weight or go-devu used for firing l 'v the cartridge, comprises a tubular memberl 29, formed in Atwo parts, divided lengthwiseand hinged to each other on one sideby a hinge pin 3II and the parts being held in closed position upon the cable by a pivoted hook 3l (see Figs. 5

and 6).

This weight is adapted to slide freely upon cable 23 and at the -lower end of its travel, to 'strike and drive pin 21 downwardly to fire cartridge C.

Mounted in..each section I0, are one or more v explosive charges and projectile carrying assemblies as illustrated in detail in Fig. 45, each assem bly including a cylindrical plug 32 which occupies a diametrically arranged aperture .33 and'intersects duct I3.

The ends of aperture 33 are enlarged or countersunk as designated by 3l for the accommodation of a head 35 on one end of plug 32 and for a nut 36 that is screw-seated onthe other end of .said plug. Y y

Packing rings 31 are positioned on yplug 32 between head 35, nut 36 and the body Il) to exclude moisture and hydraulic pressures from aperture Extending into plug 32 from the head end thereof, is a chamber 38 adapted to receive an explo-j-` sive charge C and screw-'seated in' theouter portion ofthis chamber is a short barrel 39 which receive a. projectile P.' i

A disc 4o of thin metal such as steel and a packing disc 4I of rubber or the like. are positioned between the inner end of .barrel `39 and thel explosive charge in chamber 38.

Formed in the periphery o cumferential groove-42 which communicates with duct I3 and formed in the-,plug and connecting said groove with chamber 38,-is a series of radially disposed ducts I3. When the parts of the tool are'properly assembled, the .lower end of ilame du'ct communicates with the .upper end -of the duct I3 in upper body member I0 and each duct I3 communicatesswith the corresponding groove 42 from which ducts I3 lead to the explosive. charge chambers-38,-

To preparethe tool for use,ex'plosive charges are placed in the chambers 33 and the barrels 39,.

each carrying a projectile, and screwed into the plugs with a disc I and packing disc 4 I, between each barrel and explosive charge.

Ablank cartridge C is now placed in chamber 26 with metal disc 21'L and packing disc 21b on top of said cartridge, and tubular plug 25 is now screwed into upper section I1 to seal and retain the cartridge therein.

Just before the tool is lowered into the casing, a iiring pin 21 inserted in plug 25.

When the tool has been lowered to the point where the casing is to be perforated, the go-devil is positioned on the cable 23 and at the termination of its downward sliding movement thereupon', pin 25 is struck and driven downward to puncture the discs 21e and 21b andv fire the blank cartridge C.

forzate the casing wall.

` A portion of the me from the ignited explosive charge passes downward through duct I3, thereby'ignitingthe charge in the next lower Vone of the plugs 32 andexpelling the projectile carlried thereby and such action is repeated ,'downward'ly throughout the tool, so as to successively v expel. the projectiles and perforate theV casing improved casing perforator may be made and subthroughouta length-substantially'equal to the length of the tool. Thus it will be seen that I have provided a well casing perforator that is simple in construction, inexpensive of manufacture and-very effective in performing the functions for which it is intended.

l It will be understood' that minor changes in the size,.for`m construction of the various-parts of my stituted for those herein shown vand described, without departing from the spirit of the invention, the scope oflwhichv isset forth in the ap. A

pended claims.

I claim as my invention: l. In a well casing perforator, an elongated body' composed of a plurality of detachably connected sections, vthe upper' section being provided with a cartridgeereceiving chamber, a firing pin disposed above said chamber, a duct leading down-A wardly from said chamber through the sections of vsaid body a plug removablyA seated in each section lbelow saidu'pper section, which plug is provided with an explosive charge chamber and with ducts between said chamberand said .rst mentioned in' each plug and means positioned'between said barrel and `the explosive charge in said chamber for protecting said explosive charge againstmois- I ture and hydraulic pressure. v

2. A well casing perforator as set forth in claim 1 with a'cable connected :with the upper portion of said body and a go-devil adapted to slide upon said cable and to strike said firing pin.

3. A well casing perforator as set forth in claiml I and with a protective closure positioned between said cartridge and iiring pin.

4. In a wel1` casingperiorator, an elongated body provided withga longitudinally disposed duct,

a plug removably' seated in said body and provided with an explosive 'charge-receiving chamber .which communicates with said duct, means re.

movably seated in said plug in front of said explosive charge receiving chamber for holding a .projectile and an air and moistureproof' packing Flame from the ignited charge in the cartridge Y kcharge breaks the discs 40 and 4I and forcibly between said projectile 4holding means and the explosive charge in said chamber.

5. In a wellcasing 'perforator, an elongated body provided with a longitudinally disposed duct,

` a. plug removably seated in said body and provided with an explosive charge receiving chamber,v said plug having an external groove which communicates with said duct and with short ducts leading from said groove to said chamber and a projectile carrying barrel removably seated in said plug.

6. A well casing perforator as set forth in claim 5 and with an air and moistureproof packing between said barrel and explosive charge chamber.4

7. In a well casing perforator, an elongated body composed of a plurality of detachably connected sections; theupper section being provided with a cartridge receiving chamber, a. ilring pin disposed above said chamber, a duct leading downwardlyfrom said chamberthrough the sections of said body, a plug removably seated in each l section below said upper section, which Dlllgis expels the projectile so that same is'driven out- 75 provided with an. explosive charge chamber and duct, a projectile carrying barrel removably seated with ducts between said chamber and the rst mentioned duct, a projectile carrying barrel removably seated in each plug and means positioned between said barrel and the explosive charge in said chamber for protecting the explosive charge against hydraulic pressure.

8. In a well casing perforator, the combination with a body having a longitudinallydisposed name carrying duct and a transverse opening intersecting said duct and extending entirely through said with packing means between said barrel and charge-receiving chamber.

10. The combination as set forth in claim 8 and with packing means between both ends of said plug and said body.

l1. In a well casing perforator, a body provided with a longitudinally disposed duct and with an open ended transverse opening which intersects said duct, both ends o! which opening are coun-- terbored, o! a plug removably seated in said opening, said plug having an explosive charge receiving chamber, a projectile receiving barrel seated in said plug in front of said charge-receiving chamber and means for establishing communica.- tion between said chamber and duct, a flange on one end of said plug and positioned in one of said counterbored ends of said opening and means removably seated on -the other end of said plug within the corresponding counterbored end of said opening for removably securing said plug in said opening.

12. A cartridge unit for well casing perforators having a body provided with a longitudinally disposed iiame carrying duct and a transverse socket which passes entirely through said body and intersects said duct, comprising a readily removable plug adapted to be positioned in or removed Afrom the socket in said body by axial movement, v

means for securing saiT nlug in said body, said plug having an explosive charge-receiving chamber, a projectile-receiving barrel seated in saidv plug in front of the chamber therein and said plug being provided with a duct for establishing communication between the ame carrying duct through the body and the explosive charge chamber within said plug.

MILLIO F. ALOI. 

